Check SSL/TLS Certificate

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden. It discloses that the tool performs a live TLS connection and reports issuer, validity window, days until expiry, and SANs, which are meaningful behavioral traits. It does not mention failure modes or whether the certificate chain is validated, so it is not fully exhaustive.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences with no filler. It front-loads the core operation and output, then immediately provides the intended use case. Every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

There is no output schema, but the description lists the key returned fields, which provides the necessary return-value context. Combined with the schema-covered parameters, an agent can call the tool correctly. Missing edge-case behavior such as connection failures or validation semantics keeps it from a 5.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents both hostname and port including the default port. The description adds little parameter-level meaning beyond what the schema provides, which matches the baseline of 3.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb ('Opens a live TLS connection') and a precise resource ('a hostname'), and enumerates the exact certificate information returned. This clearly differentiates it from sibling tools like check_http_status, check_dns, and check_security_headers.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly says 'Use this to diagnose SSL warnings or expiry issues,' giving a clear context for when to invoke the tool. It does not explicitly list when not to use it or name alternatives, so it falls just short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.